The evolution of brilliant iridescence in birds

Colors of iridescent feathers are some of the most striking in nature, but when and how they evolved remains elusive. Using a dataset of 71,536 body patches from 5,755 bird species, we reconstruct the evolution of iridescence. We find that brilliant iridescence, such as that of peacocks, is likely ancestral in birds, and possibly in dinosaurs, but was lost and regained multiple times over evolutionary history. Transitions from weak to brilliant iridescence were gradual, and iridescence evolved from both melanized and non-melanized patches. These findings reshape our understanding of color evolution in birds and their ancestors.